Restoring an Xbox Accounts' Purchases

I owned an Xbox One a little over 2 years ago. I stopped using it as much, only used it as an alternative to cable type things as I switched to PC around 5 years ago. For the past 2 years I have never owned an Xbox or used one in any way, but recently I
purchased an Xbox One again to play Lego games with my Fiance lol.

However, when I logged in to the account I had previously used all my digital content that had been purchased years ago had disappeared. I'm talking hundreds of dollars worth of movies, TV shows, and Games that I had owned and downloaded previously all gone.
When I checked my purchase history it stopped after 3 months and it wasn't just Xbox purchases but Microsoft Office that I had payed for was gone as well with no recording that I had ever bought it.

I looked into my account a little bit and the account had been converted to a Family account consisting of My Dad and My accounts for whatever reason and I am wondering if that may have something to do with it.

My question is, where did all of my purchases go? Can I get them back or are they gone forever? If they are "gone" is there a way I can prove I bought them using the card they were bought with, and or some other form of verification?

:)